Why Dental Fillings Fail and What to Do About It

Written by Valley Oak Dental Group on . Posted in Dental Tips

When you have a cavity, your dentist repairs it with a restorative process that most patients call fillings. The decayed portion of your tooth is removed, and then the remaining space is filled with a substance that bonds to your tooth without compromising the overall health of the tooth. Fillings are the most common dental-restoration procedure.

However, people can make the mistake of thinking that dental fillings last forever. While the replacement portion that fills the gap is hardwearing and long-lasting, it is not the same as the strength of your natural enamel. Fillings do not last forever, and when they do fail, they leave the rest of your tooth open to further decay. 

Regular dental care helps to monitor fillings to make sure they are still functional. With good dental hygiene, a typical filling has a long lifespan, but some behaviors can accelerate its decline. Learn about what causes fillings to fail, what you can do to care for them, and how to know if you might need a replacement. 

Why Failed Fillings Are So Serious

Failed fillings, especially ones that have not yet fallen out, are serious because once the seal between the filling and your tooth has broken, there is a gateway for bacteria to enter the space behind the filling. You can’t clean behind a filling with a brush or with floss, so the rate of decay is rapid.

Some people can go from simply needing a small replacement filling to needing a root canal procedure just because the filling is no longer effective. 

What Causes Fillings to Fail

There are several factors that affect the lifespan of a dental filling. These include:

  • The size of the filling. Larger cavities require larger fillings. Larger fillings have a larger surface area and larger perimeter, which means they have greater exposure to bacteria in your mouth. Teeth with large cavities are not as strong, which means they might not support the filling as long. 
  • The age of the filling. Older fillings are more likely to crack, wear down, or chip. 
  • Your dental hygiene habits. Some fillings can fall out if the tooth begins to decay further, and the decay can reach behind or beyond the original perimeter of the filling. 
  • Grinding and clenching. Your teeth can withstand a tremendous amount of force from biting, but fillings, while strong, cannot take the same amount of stress. 
  • The type of filling material. There are a few different types of fillings. Silver amalgam fillings, for example, are less popular because they don’t match the color of your teeth. But, these fillings are more durable than the prettier composite fillings. Tooth-colored fillings are more likely to wear out fast. 

Another factor that reduces the effectiveness of your fillings over time is your own lifestyle. Studies show that smoking and drinking alcohol can reduce the lifespan of dental fillings. 

How People Can Prevent Filling Failure

Your best defense against filling failure is your own good dental hygiene and lifestyle habits. Brush and floss every day, taking special care to clean teeth that have had trouble in the past. Do not overlook the need for floss. Not flossing is the reason why people get cavities between their teeth to begin with, and even after fillings, these between-teeth areas need daily care.

If you think you might have trouble with clenching and grinding your teeth, talk to your dentist about getting a mouthguard to wear at night. 

Finally, do not postpone regular dental cleaning and screening. Each time you go to get your teeth cleaned, the dentist can check your existing fillings. The x-rays will also show the early signs of filling failure, with spots of decay beginning to form along the edges of the tooth where the filling is located. 

Without these early methods of detection, you have no real way of knowing whether your filling is no longer working the way it should, unless it completely falls out. 

What Are the Other Signs to Watch For?

Unfortunately, most of the other signs that your fillings have started to go bad are also signs that the decay and harm to your tooth are much greater. You might notice that your floss gets stuck in between your teeth when you floss because the edge of the filling is catching the string where the tooth edge has worn away. 

Another sign is pain. As decay moves behind the filling, it gets closer and closer to the sensitive nerve of the tooth. Your tooth might also experience greater sensitivity to hot and cold. Without the seal between the filling and the tooth, the dentin (the soft interior of the tooth) is exposed to the temperatures of the foods you eat, and your nerves often will register this sensory input with pain. 

For more information about repairing old fillings, contact us at Valley Oak Dental Group.